Wood pencil with lead feeding mechanism



Dec. 29, 1942. J, KATTENHORN 2,306,954

WOOIS PENCIL WITH LEAD FEEDING MECHANISM Fil'ed Dec. 2, 1941 Fig. 5 Fig.6

INVENTOR HE R). I64 TF/VHOPN BY 1T ORNEY Patented Dec. 29, 1942 UNITED STATES PATENT OFFICE WOOD PENCIL WITH LEAD FEEDING MECHANISM Henry J. Kattenhorn, Leonia, N. .1. Application December 2 ,1941, Serial No. 421,281

6 Claims. (.Cl. 120-19) This invention relates to writing instruments such as pencils.

The pencil most extensively used is made of wood containing a center-positioned lead rigidly secured in place. As the lead is consumed in writing, the Wood must be cut away to expose the proper amount of the lead as well as to permit pointing of the exposed portion. This sharpening of the pencil must be made at frequent intervals and the pencil is soon worn down sufficiently to be unsightly and out of balance. It therefore is generally discarded when about half used up.

Mechanical pencils of metal, with thin leads requiring no pointing, have been proposed and used to a limited extent, but they are relatively heavy and the lead grip soon wears and permits the lead to turn. Consequently, the ordinary wood pencil is still favored by pencil users.

It is an object of this invention to so construct a wood pencil, or pencil of similar light material, that it does not require sharpening and permits the lead to be substantially consumed, after which the pencil may be discarded.

Another object of the invention is to construct a feeding device for the lead of a wood pencil,

so that it permits ready feeding of the lead but instantly checks backward motion dueto pressure on the writing surface.

A further object of the invention is to so con- Other objects will be found in the specification,

with reference to the drawing, in which:

Fig. 1 is a side view of a pencil embodying the invention with parts cut away to show the position of the operating parts when the lead is being extruded.

Fig. 2 is a partial section of the pencil showing the position of the parts when back pressure is applied to the lead by contact with the writing surface, the action being exaggerated for purposes of explanation.

Fig. 3 is a section taken on the line 3-3 of Fig. l viewed in the direction of the arrows.

Fig. 4 shows the shape of the stamped checking or locking element before it is formed into the shape shown in Figs. 1 and 2.

Fig. 5 is an end view of the locking element viewed from the left side of Figs. 1 and 2.

Fig. 6 is an end view of the pencil tip showing its construction for functioning with a triangular-shaped lead.

Referring to the drawing, the pencil l is preferably made of wood because of its lightness and low cost and other qualities that have made it the choice of the majority of pencil users. The wood need not be made of the high grade stock required for ordinary pencil manufacture and cheaper grades may be used when desired.

The wood is shaped to the usual wood pencil size and may be either round, hexagonal, or any other desired contour, but in the drawing, for simplicity, I have shown it as being round. The pencil is slotted throughout its length with a perpendicular cut 2 as by a saw and the central groove 3 is produced, either before or afterwards, in circular form by any means, though this central part could be square or other shapes when desired. This central groove will be relatively small and all dimensions, of course, will not be as large as is indicated in the drawing. It is preferably of such size as to receive the usual thin lead found on the market for use in mechanical pencils.

The pencil is pointed and a conical metal tip 4 is cemented or otherwise attached thereto. This tip may be rolled into shape from fiat metal stock having sufi'icient resiliency to grip the lead 6 and prevent it from turning during the use of the pencil. It is preferable to have the central opening 1 in this tip of non-circular form. In Fig. 6 I have indicated the shape as triangular with rounded corners, though it may be square, hexagonal or any other non-circular form. The

lead used in the pencil should have substantially the same shape as the opening in the tip.

The pencil I may, if desired, have a metal ferrule 8 crimped on the pencil to hold a suitable rubber eraser 9.

The feeding element II] is made from fiat metal stock slightly thinner than the Width of the slot 2, so as to move freely therein. This flat stock is cut out at the center portion to form an opening I I, which is slightly enlarged to form a notch I2 to receive the checking device [3 and its spring I4, later to be described in detail. This enlarged opening or slot has a short perpendicular front side l5 and a perpendicular rear side H5. The two legs l1, I8 are formed into general, though not exact, circular form IQ of approximately the diameter of the lead groove 3, as shown in Fig. 3. The feeding device is so dimensioned that it will slide freely the length of the pencil, as by pressure of the thumbnail against the protruding abutment 20, as indicated in Fig. 1. The feeding device, however, will remain in the pencil, as the legs l1, l8 prevent it from dropping out through the slot 2. I

The locking element I3 is preferably stamped out of flat stock in the form shown in Fig. 4. with a rectangular portion 2| and an integral strip 22. This stock is of spring metal, as the extension 22 forms the spring [4 that tilts the checking unit to prevent backward motion of the lead. The rectangular portion is bent into somewhat U-shape, as indicated particularly in Fig. 5, so that it has a substantially circular portion bottom portion fitting in said groove and adapted to engage the rear end of said lead, said bottom portion having a notch, a lock in said notch having a corner engaging the bottom of said backward pressure of the lead is produced by i engagement of the front side i5ioffthe-notchsl2 with the top portion 21 of the edge of the locking,

element l3, as indicated in Fig. 2.

Whenever the lead wears down sufii'ciently to require feeding, the projection 28 on the. feeding device ill may be pushed to the left inFig, 1, for example, by the thumbnail. The fiat rear side it engages the side ZE-of, the lock and thus;

compresseswealrxspring it andaligns. the lock sov that: it; will move freely forward, with the feeding movement of element .l is. applied; against the writingtsurface, the force transmitted through the leadtends to move the: feedingunit. l9 backwards, but the rear bottomedge29 of the lock is, maintainedconstantly againstthe bottom of-the groove, by the tilting action of spring i i and rearward motion cannot'take place to a noticeable extent.

place. fhe lost motion between the parts i 5 and 2 will not exceed a few thousandths of an inch.

in commercial practice and hence the backward movement of the lead in producing the locking action will not substantially exceed this minute amount before itis solidly checked.

The lead may be fed continuously, through the It will be apparent that the-locking member need not berectangular as shown. It may be of various shapes so long as the forwardpressure.

tends to tilt the lock forwards and the backward pressure tends to tilt it backwards to cause the corner or edge to bite against the wall of the groove. Also, instead of the upper part of the'reverse could be used.

It will be apparent that various other m odifications may be made in the construction without,

departing from the spirit of the invention.

Having described my invention, what I'claim is:

1. In writing devices, a pencil-shaft having a central'groove adapted to receive a lead and a slot extending into said groove, a feeding member having a top portion fitting in said slot and a bottom portion fitting in said groove and adapted to engage the rear end of said lead, said bottom portion having a recess, a lock in'said recess having an end engaging the bottom of said groove, and a spring, said tilting said lock to maintain said end against the wall of said groove.

2. In writing devices, a pencil shaft having a central groove adapted to receive a lead and a slot extending into said groove, afeeding member. having a topportio-n fitting. in said slot and a,

When pressure I This istruebecause the backward'pressure exerted lee-- tween the points and, 2? will, through slight tilting action, cause the locking to instantly takev the loci: fitting into a notchin the feeder element,,

groove and a spring fastened to said lock and engaging the surface of said groove for tilting said lock to force said corner against the bottom of said groove upon rearward motion of said .feeding member.

'3...In writing devices, a pencil shaft having a central groove adapted to receive a lead and a slot extending into said groove, a feeding member having'va. top portionfitting in said slot and a bottom portion fitting in said groove and adapted to engage the rear end of said lead, said bottom portion having a notch with front and rear sides, a lock in' said notch having front and rear sides and a base, said base slidingly fitting said groove whenits rear side is moved forward by the rear side of said notch, and aspring tilting said loci: to cause said baseto bind against the bottom of the groove when the rear side of said notch is moved away from the rear side of said In writing devices, a pencilshaft having a central groove adapted to receive a lead and a slot extending into said groove, a feeding member having a top portion fitting in said slot and a bottom portion fitting in said groove and adapted to engage the rear end of said lead, said bottom'portion having a notch with front and rear sides, a lock in said notch having front and rear sides and a base, said base slidingly fitting said groove when its rear side is moved forward bythe rear side of said notch, and a leaf spring fastened to said lock and engaging the bottom of the groove for tilting said lock to cause said base to bind against the bottom of the groove when the rear. side of said notch is moved away from the rear side of said lock.

5,... In writing devices, a pencilshaft having a central groove adapted to receive a lead and a slot extending into said groove, a feeding member having a top portion fitting in-said'siot and a bottom portion fittinginsaidigroove.and adapted to engage thev rear end of said lead; said bottom portion having, anotch with the rear side perpendicular to said groove and a front side cut away at the bottom, a lock. having front andrear sides loosely fitting-in said notch and a. base slidingly fitting said groove when itsv rear side is moved forward by the rear side of said slot and a spring tilting said'lock to cause its-base. to engag-e the bottom of the groove at'anangle when its front side is engaged by the front side of the notch upon rearward motion of said. feeding member. s

6Z Inwriting-fdevices, a pencil shaft havinga central groove, adapted'to receive a lead and a slot extending into said grooye, a feeding memher having a top portion fittingin'said slot and a bottom portion fitting in saidjgroove and adapted toiengage the rear end of said lead, said bottom portion having a notch with a rear side perpendicular to said groove'and. a front side cut away at the. bottom, a lockof substantially rectangular form loosely fitting in said notch and having a base slidingly fitting said groove when its, rear side is parallel to the rearside of said slot, and a spring tilting said loclg'to' cause its base to engage the bottom of the groove at an angle whenitsfront side isengaged by the front side of said notch upon rearward motion of, said fedeing member.

1 HENRY, J. KATTENHORN. 

